Galaxies on Instagram: "On a clear, dark night with no light pollution, the human eye can see about 2,500 to 3,000 stars at once from any one location on Earth. That’s out of roughly 5,000 to 6,000 visible to the naked eye total (since half the sky is below the horizon). If you use binoculars or a telescope, that number jumps into the hundreds of thousands to millions, depending on the equipment and conditions. But with just your eyes, around 3,000 max is what you’ll see under perfect skies."

physicsfun on Instagram: "Color Gradient Magnetic Film: a favorite device in my collection- making the invisible visible and revealing the hidden beauty of the physics in our everyday world. The field structure of six magnetic objects can be seen here. Staring with a simple dipole neodymium in the center and going clockwise from the top left: fridge magnet with stripe pattern, magnetic rotor of a small motor, ring of poles of a rotor for a stepper motor, vintage ferrous classroom “dipole”, and a